In this worksheet, we will practice converting between hydronium and hydroxide ion concentrations in water and the corresponding values of pH and pOH.

**Q1: **

The hydronium ion concentration of vinegar is approximately M. What is the corresponding value of the pOH?

- A
- B2.4
- C1.0
- D12
- E13

**Q2: **

What is the pH of a 0.0125 M solution of potassium hydroxide, ?

- A0.0125
- B1.90
- C9.99
- D12.1
- E4.01

**Q3: **

What is the pOH of a 0.0125 M solution of potassium hydroxide, ?

- A0.0125
- B12.1
- C9.99
- D1.90
- E4.01

**Q4: **

To 1 decimal place, what is the pH of at ? Assume that ionizes completely.

**Q5: **

To 2 decimal places, what is the pH of at ? Assume that ionises completely.

- A9.85
- B3.85
- C4.15
- D10.15
- E11.20

**Q6: **

To 2 decimal places, what is the pOH of at ? Assume that ionizes completely.

**Q7: **

To 2 decimal places, what is the pOH of at ? Assume that ionizes completely.

**Q8: **

To 1 decimal place, what is the pH of at ? Assume that ionizes completely.

**Q9: **

To 2 decimal places, what is the pOH of at ? Assume that ionizes completely.

**Q10: **

Calculate to 3 significant figures the hydroxide concentration of a solution with a pH of 6.52 at . The self-ionization constant of water, , is at this temperature.

- A M
- B M
- C M
- D M
- E M

**Q11: **

Coffee has a pH of about 5.1. Calculate to 2 significant figures the hydroxide ion concentration of coffee at .

- A M
- B M
- C M
- D M
- E M

**Q12: **

To 2 decimal places, what is the pH of at ? Assume that ionizes completely.

**Q13: **

To 1 decimal place, what is the pOH of at ? Assume that ionizes completely.

**Q14: **

To 2 decimal places, what is the pOH of at ? Assume that ionizes completely.

**Q15: **

What is the pOH of at ? Assume that ionizes completely.

- A2.5
- B11.8
- C11.5
- D2.2
- E1.7

**Q16: **

To 1 decimal place, what is the pH of at ? Assume that ionizes completely.

**Q17: **

The of the conjugate base of an unknown aqueous acid is 4.17. What is the concentration of the unknown acid?

- A M
- B M
- C M
- D M

**Q18: **

To 1 decimal place, what is the pOH of a 0.000259 M aqueous solution at ? Assume that is completely ionized.